The invention concerns a method for shaping a metal blank, wherein the blank is heated to a predetermined temperature, is then cooled by means of a cooling device, and is subsequently placed in a press and shaped. The invention also concerns a cooling device for a metal blank.
The term “blank” below preferably means flat sheet metal. However, the blank may already be pre-shaped and have a non-flat shape. In the present example, the blank is a flat blank.
In a conventional method that has been used for a long time, a metal blank is inserted into a hydraulic press between an upper tool and a lower tool. The tools are then moved relative to each other, thereby shaping the blank in correspondence with the shapes of the shaping surfaces of the tools.
In the so-called press-hardening method, the blank is initially heated to a temperature of approximately 800° C. to 1000° C. in order to facilitate hardening, is then inserted into the press and shaped, and held in the press under the action of the shaping or pressing force until the blank or the component shaped therefrom has cooled down to a temperature below a predetermined target temperature. Cooling takes a relatively long time. During this time, the press cannot be used further and, for this reason, the production of one single component is very time-consuming and quite uneconomical.
In order to increase the efficiency of the method, the heated blank is conventionally pre-cooled prior to insertion into the shaping press by guiding the blank through a tunnel in which air and/or inert gas is blown towards the blank, thereby cooling it down to a temperature of approximately 400° C. to 500° C. This method considerably reduces the dwell time of the blank or shaped component in the press. However, a corresponding cooling tunnel requires a large amount of space, since the cooling path must be relatively long in order to cool down the components as described above.
It is the underlying purpose of the invention to provide a method for shaping a metal blank, which realizes fast and efficient cooling and shaping of the blank, and to provide a cooling device for a metal blank for performing the method in a simple and space-saving fashion.